Internal combustion engines often include one or more turbochargers for compressing a fluid such as air, which is then supplied to combustion cylinders or chambers of the engine. Exhaust gases are directed to and drive a turbine wheel of the turbocharger. The turbine wheel is connected to a shaft that drives a compressor wheel. Ambient air is compressed by the compressor and fed into the intake manifold of the engine.
The shaft of the turbocharger is typically supported between the turbine wheel and the compressor wheel by one or more bearings contained within a bearing housing. Oil lubricates the bearings. Seals prevent oil from leaking from the bearing housing. Oil from the bearing housing leaking past the seal at the turbine end of the bearing housing may undesirably mix with the exhaust flow. Oil from the bearing housing leaking past the seal at the compressor end of the bearing housing may be undesirably carried into the combustion chamber of the engine. In addition, if exhaust gases leak past the seal between the bearing housing and the turbine housing, the exhaust gasses may contaminate the oil and reduce its lubrication and cooling capabilities.
U.S. Pat. No. 7,334,799 discloses a turbocharger for use with an internal combustion engine. The turbocharger includes a turbine and a two-stage compressor. A sealing device having a ring seal and a bellows assembly is provided to create a seal between the bearing housing and the turbine. Pressure differential between the bearing housing and the turbine causes expansion and contraction of the bellows assembly in order to improve the sealing function.
The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein nor to limit or expand the prior art discussed. Thus, the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate any element, including solving the motivating problem, to be essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims.